In recent years, it has become possible to transmit a high definition picture to client terminals such as portable terminals in association with innovation of a moving image encoding technology including MPEG (Moving Picture Experts Group)-4, and development of a communication technology. For example, it has been practiced to transmit a single stream (hereafter, referred to as “joined stream”) obtained by joining two or more picture encoding bit streams (hereinafter, referred to as “video stream”) from a server to client terminals, after multiplexing the joined stream with an audio stream, control information such as synchronous reproduction information, and header information for transmission etc.
By joining two or more video streams to generate a joined stream and transmitting the joined stream as a multiplexed stream on the server side, it becomes unnecessary to synchronize with the server side at the time of receiving the two or more video streams on a receiving apparatus side. In addition, also when two or more images are intended to be displayed simultaneously in respective positions of divided regions of a display screen, it becomes unnecessary to perform decoding processing and display processing simultaneously or to take display synchronization among two or more images. Therefore, it becomes possible to perform decoding and displaying of video streams easily in not only a computer having a high processing ability, but also in various types of receiving apparatuses such as a portable terminal and an embedded device.
For example, it is disclosed in PTL 1 that a single stream obtained by joining two or more video streams is transmitted from a server to client terminals.